From: Tetsu Yamamoto <tyamamot@redhat.com>
Date: Tue, 26 Feb 2008 19:40:21 -0500
Subject: [xen] ia64: fix kprobes slowdown on single step
Message-id: 47C4B175.5080605@redhat.com
O-Subject: [RHEL5.2 PATCH] ia64 xen: Xen slows down and almost not respond when running some systemtap script
Bugzilla: 434558

This is a fix for BZ#434558.
https://bugzilla.redhat.com/show_bug.cgi?id=434558

The debug message on every singl step trap makes kprobe run slow.  This
patch remove the message which is actually just for xen developers.

I've tested this with kernel -83 and confirmed that the message is not
shown and kprobe works well.

Please review and ACK.

Regards,

Tetsu Yamamoto

Acked-by: "Stephen C. Tweedie" <sct@redhat.com>
Acked-by: Chris Lalancette <clalance@redhat.com>
Acked-by: Don Dutile <ddutile@redhat.com>

diff --git a/arch/ia64/xen/faults.c b/arch/ia64/xen/faults.c
index 77a71b1..2c7e234 100644
--- a/arch/ia64/xen/faults.c
+++ b/arch/ia64/xen/faults.c
@@ -716,7 +716,6 @@ ia64_handle_reflection(unsigned long ifa, struct pt_regs *regs,
 			return;
 		break;
 	case 36:
-		printk("ia64_handle_reflection: handling single step trap\n");
 		vector = IA64_SINGLE_STEP_TRAP_VECTOR;
 		if (debugger_trap_entry(vector,regs))
 			return;